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Thursday, December 13, 2007

Evolution True!

In what really shouldn't come as much of a surprise researchers have shown, once again, that the things people do is conditioned by evolution. Given that we're the result of people who survived to have children as a result of the things that they did, this shouldn't be all that a startling a result.

Pregnant women may stand out a mile away with their characteristic backward-leaning stance, but that clumsy-looking position is a unique adaptation that evolved over millennia, anthropologists said on Wednesday.

Pregnant pre-humans appeared to have stood the same way. And it may save women from even more back pain than they already have, the researchers report in this week's issue of the journal Nature.

The bodies of women do two things when they are pregnant -- they adjust their stance to move the center of gravity to accommodate the growing fetus, and the lower vertebrae have evolved a distinct shape to allow this shifting to take place without damaging the spine, Katherine Whitcome of Harvard University and colleagues found.

The logic here is pretty easy to understand. Those women who didn't change their stance in this manner would have had greater back pain, greater risk of inusry. They would thus have had fewer children who themselves had such and thus the adaptation spreads through the population.

As we find ever more things that are explained by the evolutionary process, it always surprises me that there are still those who deny it.